1. Field of the Invention (Technical Field)
Embodiments of the present invention relate to solar simulators. More particularly, embodiments of the present invention relate to solar simulators for testing solar cells, particularly in close proximity thereto.
2. Description of Related Art
Typical large area simulators use a single or multiple lamps in a single lamp house disposed at distance of about a few meters to about 10 meters away to illuminate large areas. Illumination over the large area is achieved by placing the lamps at this distance away from the solar panels to be tested. This arrangement takes up a lot of floor space and requires a large test area. Homogenizing screens may also be used to improve the uniformity over the area to be tested. High power levels must be used in order to drive the lamps sufficiently to achieve the necessary power at the typical distance of 10 meters. Another issue, which is associated with the known types of large area testers, is the need for tight divergent angles of the light source on the target. This is also achieved by placing the light source at a great distance away. There is thus a need for illumination at low divergent angles, i.e. less than 1.5 degrees to as little as 0.2 degrees, for testing large concentrator photovoltaic arrays that utilize lenses that require tight divergent angles which simulate the sun.